JPS5918372A - Drying furnace for sludge - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Even if the sludge is made of low-calorie sludge or sludge with a high moisture content, it is possible to produce auxiliary fuel by using a combustion method that skillfully utilizes all the heat and energy. Invented a technology that could be used to reduce replenishment and incinerate using one's own thermal energy, and applied for a patent (Japanese Patent Application No. 5-5-169165)
) I am doing everything. Figure 1 shows this sludge incineration/stem.

Before explaining the present invention, the sludge incineration system shown in FIG. 1 will be explained first.

The sludge whose moisture content has been reduced to a total of 90% to 70% by mechanical dewatering is stored in the hopper 1. A forced feeding means 2', such as a screw conveyor, is provided in the lower part of the hopper 1 to forcibly feed the sludge to the heater 3,
The sludge heated by the heater 3 and completely imparted with fluidity is then fed into a drying furnace 4 having a fluidized sand bed. The dry product produced in the drying oven 4 is sucked and crushed by a blower 11 and introduced to a separation means 5, where it is separated into a solid content of dried sludge and a gas content of dried sludge. . The separated solids are transferred to a combustion furnace 7 by means of feeding means such as a screw conveyor 6.

7'. FIG. 1 shows a two-stage combustion furnace system including an incomplete combustion furnace 7 and a complete combustion furnace 7'. The combustion blast air is blown by the blower 13, and after being preheated by the metal air preheater 14 provided on the outer periphery of the complete combustion furnace 7', it is divided proportionally and supplied to the incomplete combustion furnace 7 and the complete combustion P7'. Ru. The gas produced in the complete combustion furnace 7' is sucked 7 by the exhaust air 1u and then transferred to the heat exchanger 8.
During pregnancy, smoke is exhausted through the entire filter 9. The separation means 5
Separated by! '1. The gas is pressurized to about 1000111111 water column by air blast + i & 11, heated to 200°C to 400°C by heat exchanger 8, and pneumatically blown by circulation circuit 12. The other part is supplied to the drying oven 4 having a drying oven 4 as a drying gas, and the other part is sent to the heater 3 as a gas for heating eggs.

The gas heated in the heater 3 is led to the drain separation means 15, discharged to the outside of the drain wire, and then taken out by a gas fuel supply pipe (716) and supplied to the combustion furnace 7, for example, as gas fuel.

FIG. 2 shows a sectional view of a sludge drying furnace according to the present invention. This is compared to a drying oven with a fluidized sand bed designated by the symbol 4 in FIG.

Approximately 30crIL in diameter and approximately 2m in height supported by support legs 21
The furnace body 22 has a drying gas supply pipe 23 at its bottom. It has two dry product take-off pipes at the top and a sludge supply front 25 at the side wall. 1. There is a dispersion plate 26 at the bottom of the furnace.
The distribution plate has many holes or nozzles 27°27
'...? I have one. The aperture ratio of the distribution plate is 0009 to 0.023. The sand layer 28 on the dispersion plate is composed of sand grains with a diameter of 1.4 tm to 2.0 mm.The thickness of the sand layer when it is stationary is about 30 c1rL, but the drying gas is blown out.
When the sand is poured in a fluid state, the thickness of the sand layer is approximately 45 cnl.

The sludge drying furnace of the present invention has a shaft 2 on the center line of the sludge 2G.
9 is provided, and a rotating blade 30 is attached to the shaft 29. The length of the blade is approximately 14 CTL, or the circumference of the blade is approximately 29 CTL. The shaft extends downward from the furnace body 21 and is rotated by a driving means 31 at a speed of 10 to 20 revolutions per minute.

The sludge drying furnace of the present invention supplies sludge to the drying furnace! @tube 25
A sufficient amount of high-pressure and high-temperature gas is supplied from the drying gas supply pipe z3 to divert the unsupplied sludge, and this drying gas is supplied from the lower space 23 to the distribution plate 2.
The sand is ejected upward through all of the jet holes 27, 27' of 6, and the sand nozzle 28 above the dispersion plate 26 is fluidized by this jet stream. The pressure of the gas in the space 32 is 100 water columns.
The temperature of the gas is between 200°C and 400°C.
It is. This drying gas content is the distribution plate 260 open"tt rate 0
．． The velocity of the material ejected upward from the holes 27, 27', etc. of 009 to α023 is 150 m to 300 m per second.
Therefore, the floating type of Sand No. 28 flows at approximately 45 CIrL.

The sludge is transferred from the sludge supply pipe 25, which has an open location on the furnace side wall, to the furnace body 2.
The sludge is supplied in the form of lumps into the fluidized sand layer and falls onto the fluidized sand layer, but if the sludge lumps are not crushed quickly, they will sink into the no of the fluidized sand and eventually settle to the no bottom, causing a problem.

The object of the invention is to make it possible for the sludge lumps falling on the top of the fluidized sand layer to sink deeply into the fluidized sand layer circle and then be crushed before being completely submerged under pressure, thus facilitating drying. It comes out.

For this purpose, as described above, the entire rotary blade 30 is rotated by the fluidized sand/*28F'l. That is, in the case of general fluidized sand, the drying gas and sand are mainly blown upward and fluidized, and the supplied sludge is hardly moved in the same direction. The sludge mass is mainly sheared by the holes in the dispersion plate or by the airflow of gas effortfully ejected from the nozzle, making it fine and spreading. By tilting the blades slightly upwards or by allowing the blades to scoop up all of the sludge at the bottom end of the jet air stream containing many different gases, the blades can bury some of the sludge before the sludge mass settles. Grinding is carried out.

Further, the structure of the rotary blade attached to the sludge drying furnace according to the present invention, which has an inner diameter of 30 cm and a height of about 2 m, has two blades with a length of 14.5 cm from the center to the blade end. The rotating feather #! As a result of experiments conducted by rotating the motor at various rotational speeds, the conclusions obtained are as follows.

The %3 diagram shows the relationship between the rotating furrows of the rotary blades and the sludge treatment volume, with the horizontal axis representing the total number of revolutions per minute of the rotating blades and the vertical axis representing the sludge throughput 1 (g/hour).

As is clear from the graph in Figure 3, the throughput is quite large when the number of rotations of the rotary blade is 1 or less than 1 Q rprn (at 10 rpm, the amount of processing becomes 1 shift, which is high, and at about 2 orpm, it becomes flat. It was found that even if the rotation speed was increased beyond that, the throughput would increase by 7 Jl.

FIG. 4 is a graph showing the rotational speed of the rotary blade and the wear state of the rotary blade.

As shown in the graph in Figure 4, the number of rotations of the rotating blade is 2.
It was found that the amount of wear caused by the fluidized sand on the blade mechanism is low up to 200 rpm, but when the rotation speed exceeds 2 Orpm, the amount of wear increases noticeably, and the length of the blade mechanism is significantly shortened. .

Therefore, in a sludge drying furnace with a diameter of 30 crIL, the rotational speed of the rotary blade having a diameter close to the inner diameter of the rotor should be l Q rpm to 20 rpm'. In other words, the #l movement of the tip of the rotary blade can be determined within a practical range of 0.7 m to 0.16 m per second (J) considering production volume and wear.

[Brief explanation of drawings]

Figure No. 1 shows the sludge disposal system that was developed and patented by the present inventor. FIG. 2 is a vertical sectional view of the sludge drying furnace according to the present invention. Figure 3 is a Venus graph showing the relationship between the rotational speed of the rotating blade and the amount of sludge treated. Figure 4 is a graph showing the relationship between the number of rotations of the rotating blade and the amount of wear and tear on the rotating blade. 1 is a hopper, 2 is a screw conveyor which is a forced feeding means, 3 is a heater, 4 is a drying furnace having a complete bed of fluidized sand, b is a separating means, which is a cyclone, 6 is a screw conveyor which is a foot feeding means for solids, 7 is a combustion furnace 8 10 is a heat exchanger 9 is a filter 10 is an exhaust fan 11 is a blower 12 is a circulation circuit 21 is a support leg 22 is a furnace body 23 is a drying gas supply pipe 24 is a drying product proboscis extractor 2b is a sludge collector 2G is Dispersion plate 27 is an ejection hole, 28 is a sand nozzle, 29 is a shaft, 30 is a rotating blade, 31 is a driving means, and 32 is a lower space below the dispersion plate y7! J'1 figure %3 figure mouth I feather / ly'pm v4 flash times my feather ηrpm

Claims (1)

[Claims] A rotary blade 30 is installed in the fluidized sand layer 28 on the dispersion plate 26 by slowly rotating the blade tip at a linear velocity of IJ per second within the range of 07 m to 0.1677 Z to give horizontal movement to the fluidized sand. The Ruru sludge drying furnace is unique in that it is equipped with a drying furnace for sludge.